Official Solution: Bunuel
A teacher distributes a batch of 56 cookies among \(x\) students such that each student receives exactly \(y\) cookies, where \(y > 0\), with some cookies left over. If these leftover cookies were redistributed, all except eight students would receive one additional cookie.
Select for
x the possible value of \(x\), and select for
y the possible value of \(y\) that would be jointly consistent with the given information. Make only two selections, one in each column.
The number of cookies initially distributed was \(xy\).
Since redistributing the leftover cookies would give all except 8 students an additional cookie, the number of leftover cookies must have been \(x - 8\).
This also indicates that there were more than 8 students in the group, so \(x > 8\). Thus, we get \(xy + (x - 8) = 56\), which simplifies to \(x(y + 1) = 64\). This implies that \(x\) must be a factor of 64. The factors of 64 greater than 8 are 16, 32, and 64.
If \(x = 16\), then \(y = 3\).
If \(x = 32\), then \(y = 1\).
If \(x = 64\), then \(y = 0\), which is not possible since we are given that \(y > 0\).
Therefore, the possible pairs \((x, y)\) are \((16, 3)\) and \((32, 1)\). Among these pairs, only \((16, 3)\) is included in the options.
Correct answer: x
"16"y
"3"